Leptin as a reproductive modulator: An eco-physiological approach

The survival of a species in an unpredictable ecosystem as the desert depends among others on the adaptation of its reproductive system, in terms of matching reproductive activity with water and food availability in the habitat, and halting it when these are limited. Integration of the various environmental cues will eventually determine which populations will be able to breed at an appropriate time thus surviving as a species in xeric environments. Osmotic stress was noted as an effective internal signal for reducing reproductive activity in desert-adapted Acomys populations. In the basis of our study lies the assumption that a possible mechanism by which dietary salinity causes an osmotic stress, which affects reproduction in desert adapted common spiny mice Acomys cahirinus in association with osmoregulatory hormones; vasopressin and aldosterone. As leptin regulates energy intake, it seemed of great interest to assess its role in reproduction of desert adapted rodents, inhabiting an unpredictable environment. For a long time energy source storage seemed as the only role of WAT, apart from providing thermal and mechanical insulation. For now WAT in our understanding is a highly dynamic, endocrine tissue, being involved in a wide range of physiological and metabolic processes far beyond the paradigm of fuel storage. White adipocytes secrete several major hormones, protein signals and factors, most notably is the peptide hormone leptin. Circulating leptin levels serve as a signal for the state of body energy repletion to body cells most importantly the central nervous system (CNS) where it suppresses food intake and permits energy expenditure. In addition to its metabolic effects, leptin is well known as a modulator of reproduction.